The invention relates to an enclosure for a target processing machine, such as a lithography or an inspection machine.
An example of such an enclosure is published in the International Publication WO2013/037802 which is assigned to the owner of the present invention. The target processing machine as disclosed in WO2013/037802, such as a lithography or inspection machine, comprises a rigid base plate, a projection column for projecting one or more optical or particle beams on to a target, a support frame supporting the projection column, the support frame being supported by and fixed to the base plate, a stage comprising a movable part for carrying the target and a fixed part being supported by and fixed to the base plate. This target processing machine is arranged inside an enclosure, also referred to as a vacuum chamber, encloses the support frame and the column. The enclosure is arranged for providing and maintaining a vacuum environment in the interior space of the enclosure. The enclosure comprises the base plate, forming part of the enclosure, and a plurality of wall panels supported by and fixed to said base plate. The enclosure comprises a door frame for one of the side walls, and a door being substantially the size of as a wall panel and fitting into the door frame.
The International Publication WO2012/080278 which is assigned to the owner of the present invention, discloses a lithography system unit comprising a lithography apparatus that is contained in its own vacuum chamber. A side of the lithography system facing a free area provided for service purposes comprises a load lock system for transferring substrates into and out of the vacuum chamber, and also comprises an access door that can be opened for such service purposes. The lithography system units are thus provided with a door at the same side as the load lock system. The door is removable attachable, and is removable in its entirety, for example using a transfer unit. The transfer unit is arranged to support the door and comprises one or more transfer elements, such as wheels or rails. The lithography apparatus is supported by a supporting structure for positioning the lithography apparatus at an elevated position. The load lock system is integrated into the door.
The U.S. Pat. No. 4,948,979 discloses a vacuum device comprising a vacuum working chamber for performing a predetermined process to a material such as a substrate, and a vacuum prechamber for changing the material. Both the vacuum chambers are coupled by a coupling member so as to communicate the interiors of the respective chambers and the communication is managed by valve means located for the coupling member. The vacuum chambers may be constructed so as to be movable or pivotable horizontally with respect to each other. According to the construction of this vacuum device, a vacuum leaking operation, a vacuuming operation, and the material exchanging operation is performed in the state with both vacuum chambers being separated to eliminate the transferring of the vibration of one of the vacuum chamber, to precisely carry out the various processes without being influenced thereby. Accordingly, during each material exchanging operation the vacuum chambers need to be separated and coupled to each other, thus requiring much time and labour. In addition, when coupling the vacuum chambers, the front surfaces of the coupling members have to be contacted to each other when the coupling members are to be connected. Although not described in detail in the U.S. Pat. No. 4,948,979, when the coupling members are connected, they need to provide a vacuum tight coupling. How this vacuum tight coupling is obtained is not described in the U.S. Pat. No. 4,948,979.
To obtain a vacuum tight coupling between the chamber, an accurate and careful alignment of the vacuum chambers with respect to each other is required. In particular an accurate and careful alignment of the vacuum prechamber with respect to the vacuum working chamber during the coupling of the vacuum chambers is required, in order to arranged the front surfaces of the coupling members in a vacuum tight contracting manner and to ensure maintenance of the vacuum condition inside the chambers.
It is an object of the present invention to provide a novel and improved enclosure for a target processing machine, which in particular allows a more accurate alignment between the target processing machine and a transfer device, such as a load lock system for transferring targets into and out of the target processing machine inside the enclosure.